Relaxation Behavior of Collagen

Abstract

The dynamic mechanical properties of purified collagen from bovine tendon were studied using a torsion pendulum in the temperature range of 120 degrees -360 degrees K at 0.3-1 cps. In the temperature range studied, two loss peaks were observed: a beta-peak at about 200 degrees K, and an alpha-peak approximately five times larger at about 280 degrees K. The temperature of the alpha-transition is shown to be dependent on water content, decreasing with increasing amount of water and shifting to lower temperatures. Broad-line proton magnetic resonance results were also obtained on similar samples. A narrow nuclear magnetic resonance (NMR) line appears at about 250 degrees C. The effects of shrinkage to form gelatin and of cross-linking on the relaxation behavior of collagen were also studied. The motions taking place in collagen over the 120 degrees -360 degrees K range are discussed.

Piezoelectric and related properties of hydrated collagen

“…Hydration's influence on molecular motion of collagen has been investigated by measuring dielectric properties (1 1, 12), elastic properties (14-16), and nuclear magnetic resonance properties (16,21). Chang and Chien (12) reported dielectric relaxations at -80°C, 10°C, and 88°C at 100 Hz for reconstituted collagen with 12 wt% moisture content.…”

“…Baer et al (14) observed elastic relaxations around -90°C, -10C, and 130°C at about 1 Hz for collagen with 10 wt% moisture content. Stefanou et al (16) reported elastic relaxations at -80°C and -20°C at 1 Hz for collagen with 10 wt% moisture content. They also noted two step decreases of second moment in nuclear magnetic resonance at -70°C and 0°C for collagen with 6.5 wt% moisture content.…”

“…But to obtain molecular interpretations, studies on purified collagen are required. Dielectric relaxations (9)(10)(11)(12) and mechanical properties of collagen (13)(14)(15)(16) have been studied. It is known that piezoelectric constants of collagen vary significantly with temperature and hydration (6,17).…”

Biomolecular Piezoelectric Materials: From Amino Acids to Living Tissues

“…The interesting point about piezoelectricity in the cornea and sclera is that as they dehydrate, the piezoelectricity is significantly reduced. It is known that piezoelectric constant of collagen vary significantly with hydration 135,167. The skin is also a well‐known piezoelectric living tissue in the human body.…”

“…It is known that piezoelectric constant of collagen vary significantly with hydration. [135,167] The skin is also a well-known piezoelectric living tissue in the human body. In 1967, piezoelectricity on the skins from human, cat, and pig was measured by Shamos et al and was speculated to be due to the oriented collagen fibrils.…”